Illuminated telephone dial



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April 24, l1934. M "E, MUSE 1,955,972

ILLUMINATED TELEPHONE DIAL .orginl Filed March 29. 1932 2 sheets-sheet 1 MEMUSE' y ATToRNEY INVENTOR K v April 24, 1934. ME. MUSE 1,955,972

J3 v o` y. FINGER ILLUMINATED TELEPHONE DIAL Y* original Filed Maron 29, 1932 2 sheets-sheet 2 Egg l ATTORNEYS Patented Apr. `24, 1934 1,955,91z- J mLUmNATEn TELEPHONE DIAL Melvin Edward Muse, Richmond, Va., assigner to I William Floyd Lee .-11 Claims. (Cl. 179-81) This applicationis a division of my co-pending application, Serial No. 601,756, led March 29, 1932. The invention relates to the art o! il. lumination and particularly to that branch of the art which deals with luminous discharge lamps.

Much consideration has been given to the problem of providing special illumination for the dial of an automatic telephone so. that it can be seen distinctly no matter where the telephone might be located. Various types of lamps have been proposed for this purpose, but so far as I am aware, none has had practicalapplication because no one hasyet devised a lamp whichanswers all of the requirements. These requirements are both physical and electrical. From the physical standpoint,-

the shape and size of the lamp must be such that it can be positioned where it will not be in the 11-.11of Fig. 10.

way to the least extent so that there can be no possible objection to its presence. From the electrical standpoint, it should be a low voltage lamp and thus capable oi operation from the standard 24 volt telephone circuit; and yet it should be capable of withstanding the electrical surges which take place during dialing and which 25 sometimes increase the voltage to as much as 800 volts or more.- v

I have provided a lamp which answers all of these requirements. It is of the luminous dis'- charge type and can be given such Aphysical characteristics that it can be combined'with the dial structure of the telephone so as to properly illuminate itvand yet its presence is hardly-:no-

ticeable. Notwithstanding the fact that the luminous discharge type the lamp is otoperating at a voltage as low'as 24 volts, and

can therefore be connected directly. to the telephone circuit. Moreover, it is capable of withstanding the large increases in voltage which ltake place during dialing'. l

The lanip itself will ilrst be described and then the manner in which it may be associated with the telephone dial ande'lectrically connected in the telephone circuit will be explained.

In the accompanying drawings:

, Figure 1 is a horizontal section of a lamp emsbodying the invention.

Fig. 2-is a horizontal section of a modified form of the lamp.

Fig. 3 is a transverse section taken on the line 3-3 of Fig. 1.

Fig. 4 illustrates how several lamps of the type shown in Fig. -2may be connected in multiple', each lamp being represented in horizontal section.

Fig. 5 is a horizontal section of a lamp of the kind shown in Fig. 2, but which has been given a ring-like shape to adapt it for use in combination with a telephone dial.

Fig. 6 is a transverse section 6-6 of Fig. 5.

Fig. 'I is a diagrammatic view-showing how the lamp may be connected in the` telephone circuit.

Fig. 8 is a vertical section of the dial mechanism of a telephone showing the lamp associated therewith.

Fig. 9 is a horizontal section taken on the line 9-9'of Fig. 8. Fig. 10 is a vertical section through the dial mechanism of a telephone illustrating another way in which the lamp may be associated therewith; and

Fig. 11 is a horizontal section taken on the line aken on the line Referring iirst to Figs. 1 and 3, the lamp comprises a tube 1 made of glass or other transparent material. It contains three electrodes,

'2, 3, and 4, suitably supported within the tube and held in spaced relation as by means of the supports 5 and 6 made of glass or the like. The electrodes may be made of nichrome, tungsten, silver, or any other suitable material. The electrodes 2 and 4 are electrically connected by lead-in wiresv 7 and 8 to the same side 9 of an.

external circuit. The electrode 4'is connected in series with a high resistance 10. When the lamp is connected to a telephone circuitthis resistance should be of the order of 100,000 ohms. The rem nglectrode 3 is connected by means of a lead-in'fwire 11 to the other side 12 of the external`circuit. The lead-in wires 7, 8, and 11 are sealed lin the glass tube as represented in the. drawings. Located within the tube against itsl wall is a defiector 13 which is .electrically connected with the electrode 3 as represented at 14, The deector may be made of chromium, silver, or any other material which is a conductor oi. electricity and which is capable of receiving a high polish. The deilector may be formed of thin metalor may be electrically deposited on the glass. I

The tube is iilled with helium, neon, or mercury vapor, or any mixture of these gases. Preferably, it 4contains all three of the gases in combi'nation'. v A mixture of the thre'e gases has been found especially suitable where'the lamp isv to 105 operate at low voltages. The helium gas is believed to be the principal one. The-others may be added as desired to suit special conditions'. II the neon is omitted altogether, the4 lamp will give a white light and can be operated at about volts, but for a very low voltage lamp the use of neon is advisable because it, when used with the other gases, still further reduces the required voltage and the current consumption.

The electrode 4 is preferably coated with a radioactive substance such asthorium or cerium oxide. The electrodes 2 and 3 may likewise coated if so desired.

The electrode 4 is the starting electrode as it causes the initial ionization of the gas. Its thorium coating makesit more effective for this purpose, especially at low voltages, and also causes the glow to be continuous. The deector 13 materially aidsy in the ionization of the gas by deecting the electric charges back to the interior of the tube. It also serves as a reflector of the light. The delector should be as long as possible from the electrical and light-reilecting point of View, but as short as necessary to obtain the desired amount of direct illumination.

The lamp shown in Figure 2 is structurally the same as that shown in Figure 1, but the circuit connections are'dierent. In Figure 2, the electrode 2 is connected to the external lead 12, and the electrodes 3 and 'i are connected to ,the external lead 9. In this case, the electrode 3 is the starting electrode and is connected in se- Vries'with the resistance 10. The electrode 4, in this case, is the one which is electrically connected tothe deilector 13. At the present time, prefer the circuit arrangement shown in this iigure. y

Figure 4 shows several lamps connected in multiple, the circuit connections being the same. as shown in Figure 2.

The tube of the lam'p may be made in the shape of a ring as shown at 15 in Figure 5. The lamp is preferably given this shape when it is to be associated with the dial of an automatic telephone in the manner hereinafter described.

`The electrodes in this case are likewise given a ring shape as represented at 2', 3', and 4'. The deector, corresponding to the deflector 13 in Figures 1 and 2, is represented at 13 and is so located within the tube that it will reect the light radially outward. 1

The way in which a lamp of the kind shown in Figure 5 may be associated with the dial of an automatic telephone is shown in Figures 8 and 9. The number plate of the dial is represented at 16. It is usually held in place by the edge of a clamping disc 17. I modify this discv to the extent of elevating it slightly and also extending it radially a sucient distance for it toact as a shield for the lamp which is positioned /just under its marginal edge. The light reflected outwardly by the delector 13' thus shines directly on the number plate 16. The usual ringer disc which rotates above the number plate is represented at 18. l

In Figures 10 and 11, the lamp is located under the number plate. In this case, the numbers and letters are cut out of the number plate so Athat the light from the lamp may shine 'through will be illuminated only when the telephone receiver is oif" the hook. Figure 7 shows a circuit arrangement which will accomplish this. When the telephone receiver 22 is on the hook 23 the supply of current to the lamp will be interrupted, but when the receiver is aremoved from the hook, the necessary connections are established to supply current to the lamp and cause it to illuminate the dial; i

, It will now be seen that from the physical standpoint, the lamp is Well adapted for use in combination* with a telephone dial. From the electrical standpoint, it is also well adapted for this use because it is capable of operating at a voltage as low as 24 volts. It will also stand much higher voltages such as occur during dialing.

I claim:

1. The combination with the dial of an automatic telephone of a luminous discharge lamp for illuminating the dial, the lamp comprising a ringlike tube located adjacent to the number plate .of the dial and being electrically connected with the telephone circuit and adapted to be operated thereby.

2. The combination with the dial of an automatic telephone of a ring-like transparent tube located adjacent to the number plate of the dial, saidtube containing a plurality of electrodes and an ionizable gas, the electrodes being electrically connected in the telephone circuit and adapted when energized thereby to produce in conjunction with Athe ionizable gas aluminous glow to illuminate the gures on the telephone dial.

3. 'Ihe combination with the .dial mechanism of an automatic telephone of a luminous discharge lamp for illuminating the dial, .the lamp comprising a ringflike tube housed by the dial mechanism, a plurality of electrodes, and an ionizable gas within the tube, the electrodes being electrically connected in the telephone circuit and iid adapted when energized thereby to produce in conjunction with the ionizable gas a luminous glow to illuminate the figures on the telephone dial. i

d. The combination with the dial mechanism l2@ of an automatic telephone oi a luminous discharge lamp for Villuminating the dial, said lamp comprising a casing, three electrodes in the cas= ing, at least one ci said electrodes being coated with a radio-active substance and a gaseous 125 atmosphere in the casing fcomposed at least in part of helium, the elect gdes being electrically connected in the telephone circuit and adapted when energized thereby to produce in conjunc-= tion with the gaseous atmosphere a luminuos glovvy i3@ to illuminate the figures on the telephone dial.A

5. The combination with the dial mechanism of an automatic telephone of a luminous discharge lamp for illuminating the dial, said lamp comn1 prising a casing, three electrodes in the cashig, i135 at least one of said electrodes being coated with a radio-active substance, a gaseous atmosphere in the casing composed at least in part oi helium, and a deector located against and covering a part only of the wall of said casing andA electricalla@ ly connected with one of the electrodes, the electrodes being electrically connected in the telephone circuit and adapted when energized there by to produce in conjunction with the gaseous atmospheres. Iluminuos glow to illuminate the i143 figures on the 'telephone dial.

6. The combination with the dial mechanism of anv automatic telephone oi a luminous discharge lamp for illuminating the dial, said 'lamp ccm= prising a casing, three electrodes in the casing, liti@ the casing composed at and a deector located a gaseous atmosphere in least in4 part of helium, against and saidcasing and electrically connected with one of the electrodes, the electrodes being electrically connected in the telephone circuit and adapted when energized. thereby to produce in conjunction with the gaseous atmosphere a luminous glow to illuminate the figures on the telephone dial.

7. A combination in accordance with claim 5- in the casing neon covering a part only of the wall ofV mosph'ere in the casing comprising a mixture of helium, neon and mercury vapor, the electrodes being electrically connected in the telephone circuit and adapted when energized thereby to produce in conjunction with the gaseous atmosphere a luminous glow to illuminate the figures of the telephone dial.

10. The combination'with the dial mechanism of an automatic telephone of a luminous discharge lamp for illuminating the dial, said lamp comprising a casing, three electrodes inthe casing, and a gaseous atmosphere in the casing comprising a mixture of helium, neon and mercury vapor, the electrodes being electrically connected in the telephone circuit and adapted when energized thereby to produce in conjunction with the gaseous atmosphere a luminous glow to illuminate the figures on the telephonedial.

11. The combination with Athe dial o1' an automatic telephone of a luminous' discharge lamp for illuminating the dial, said lamp being electrically connected with the telephone circuit and adapted to be operated thereby.

MELVIN EDWARD MUSE.

liso 

